Table 4.

Estimated ORs (95% CI) for being in one higher category of breast density (Modified Wolfe's classification) by 1 SD increase in explanatory variables estimated by sequential logistic regression analysis

Mean ± SDOR* 95% CIOR 95% CI
Measures of adiposity
    BMI, kg/m224.4 ± 3.80.34 (0.25, 0.46)0.36 (0.26, 0.49)
    Truncal fat percentage32.6 ± 7.60.35 (0.26, 0.47)0.38 (0.28, 0.51)
Fasting serum variables
    HDL-cholesterol, mmol/L1.53 ± 0.331.77 (1.36, 2.32)1.63 (1.24, 2.14)
    Total/HDL-C ratio3.01 ± 0.800.54 (0.41, 0.70)0.57 (0.43, 0.74)
    LDL-C/HDL-C ratio1.75 ± 0.700.60 (0.46, 0.78)0.64 (0.49, 0.83)
    Insulin, pmol/L85 ± 590.66 (0.50, 0.87)0.68 (0.52, 0.89)
    Leptin, pmol/L858 ± 5610.49 (0.37, 0.64)0.52 (0.39, 0.69)
Salivary hormones, pmol/L
    Overall estradiol18.3 ± 9.41.00 (0.78, 1.28)1.09 (0.84, 1.41)
    Midluteal estradiol20.0 ± 11.10.89 (0.68, 1.15)0.97 (0.74, 1.27)
    Overall progesterone131.4 ± 68.71.33 (1.02, 1.73)1.32 (1.01, 1.73)
    Midluteal progesterone164.0 ± 87.61.41 (1.07, 1.86)1.36 (1.03, 1.81)
  • NOTE: The Norwegian EBBA study (n = 205). ORs shown are for each measure of adiposity, serum variable, and salivary hormone after adjustments.

  • The conversion factor from mmol/L to mg/dL is 38.7 for HDL-C. The conversion factor from pmol/L to milliunits/L is 0.17 for insulin. The conversion factor from pmol/L to ng/dL is 1.5 for leptin. The conversion factor from pmol/L to pg/mL is 0.272 for estradiol and 0.314 for progesterone.

  • * Adjusted for age.

  • Adjusted for age, age at menarche, parity (nullipara, parous), and past use of hormonal contraceptives (ever, never).